Working with Arrays 7 5 FIGURE 4.21 Creating a polar array 9. Click any one of the chairs to select the polar array. Hover the cursor over the base point grip, and choose Stretch Radius (see Figure 4.22). Type 5f9g (or 175 in metric); then press Enter and Esc. The chairs more closely wrap around the smaller table. 10. Save your work as Ch4-E.dwg (or Ch4-E-metric.dwg). FIGURE 4.22 Editing a polar array with its grips
7 6 Chapter 4 • Editing Entities Divide and Measure The DIVIDE and MEASURE commands do not copy objects in a rectangular grid or around a center point as does the ARRAY command. Instead, these commands are used for arraying points. DIVIDE splits up a path into any number of evenly spaced points. MEASURE lays out points at a set distance, often leaving a remainder at the end of a path. You’ll use DIVIDE in Chapter 5, “Shaping Curves.” Trim and Extend The TRIM and EXTEND commands are opposites. You can invoke the opposite command while running either by holding down Shift. This method is especially helpful because TRIM and EXTEND are often used together, as you’ll see in this procedure: 1. If the file is not already open from performing the previous step, go to the book’s web page, browse to Chapter 4, download the file Ch4-E. dwg (or Ch4-E-metric.dwg), and open it. 2. Navigate to Stair B in the building’s core. 3. Click the Extend tool on the Modify panel (it is nested under Trim). Select the inner line of the bottom core wall and press Enter. This line will be the boundary edge that you will extend the stair treads to meet. 4. Create a crossing window by clicking points A and B as shown in Figure 4.23. Four tread lines are extended. Click each remaining tread line, one at a time, to extend all the stair treads to the core wall. Press Enter to end the command. 5. Type TR (for Trim), and press Enter. Select the upper and lower handrail lines to act as cutting edges and press Enter. Make a crossing window in the center of the handrail to trim away all the treads that pass through the handrails, and press Enter. 6. Press Enter twice more to repeat the TRIM command, and select all edges as potential cutting edges. Then click the single tread line that Certification Objective
Lengthen and Stretch 7 7 extends below the break line and press Enter. Stair B should now be the mirror image of Stair A. 7. Save your work as Ch4-F.dwg (or Ch4-F-metric.dwg). B A FIGURE 4.23 Extending lines with a crossing window and by selecting Lengthen and Stretch The LENGTHEN and STRETCH commands are similar in how they can increase the length of objects. However, STRETCH is the more flexible of the two, allowing you to reposition interconnected objects. Let’s lengthen a line and stretch a door within a wall: 1. If the file is not already open from performing the previous step, go to the book’s web page, browse to Chapter 4, download the file Ch4-F. dwg (or Ch4-F-metric.dwg), and open it. 2. Navigate to the Copy Room. Notice that there is a problem with the copy machine by the door; the bottom line is drawn only halfway. Although you could use FILLET or EXTEND to fix it, type LEN (for Lengthen) and press Enter. The command prompt reads as follows: Select an object or [DElta/Percent/Total/DYnamic]: Type P (for Percent), and press Enter.
7 8 Chapter 4 • Editing Entities 3. Type 200, and press Enter. Click the line segment on the right side to lengthen it toward the right. The copy machine is fixed! 4. Type S (for Stretch). The command prompt reads as follows: Select objects to stretch by crossing-window or crossing-polygon... Select objects: Implied windows won’t work for STRETCH; only crossing windows or crossing polygons are acceptable. Click points A and B as shown in Figure 4.24 to select the objects to stretch and press Enter. B A FIGURE 4.24 Stretching walls, a door, and its swing 5. Using either Polar Tracking or Ortho mode, move the cursor down vertically, type 2f6g (or 75 for metric), and press Enter to specify the second point. The wall, door, and swing end up more or less centered on the wall. 6. Save your work as Ch4-G.dwg (or Ch4-G-metric.dwg). Certification Objective
Offset and Mirror 7 9 Offset and Mirror The OFFSET and MIRROR commands are often used to create new objects. OFFSET creates an object a set distance on one side of the original object. MIRROR creates a reversed object at a distance from the original object as determined by the position of a drawn reflection line. Let’s explore these commands: 1. If the file is not already open from performing the previous step, go to the book’s web page, browse to Chapter 4, download the file Ch4-G.dwg (or Ch4-G-metric.dwg), and open it. 2. Click the Offset tool in the Modify panel. The command line reads as follows: Specify offset distance or [Through Erase Layer] <Through>: Type 4, and press Enter. Select the elliptical arc at the bottom edge of the Copy Room. 3. The command line asks you to specify a point to determine on which side of the selection to offset the new object. In this case, click anywhere above the elliptical arc and a new ellipse is created such that its curvature matches the original but is spaced 4 units away. Press Enter to exit the command. 4. Type F (for Fillet), press Enter, and click the new elliptical arc and the inner line of the adjacent vertical wall on the right. Press the spacebar to repeat the FILLET command, and click the elliptical arc and inner line of the adjacent vertical wall on the left. The intersections between the wall objects are cleaned up (see Figure 4.25). 5. Zoom into the furniture system that is missing two desks in the upper-right quadrant of the building. Click the Mirror tool in the Modify panel. Make crossing and individual line selections to select the desks and chairs shown in Figure 4.26, and press Enter. The command line reads as follows: Specify first point of mirror line:
8 0 Chapter 4 • Editing Entities FIGURE 4.25 Offsetting and filleting walls A B FIGURE 4.26 Mirroring furniture blocks Click point A, and then move the cursor up and click point B to draw the mirror line. Press Enter to end the command.
O ffset and Mirror 8 1 6. Press Enter to repeat the MIRROR command. Double-click the mouse wheel to zoom to the drawing extents. Select the furniture system you rotated with the Reference option in the upper-right building quadrant and press Enter. For the first point of the mirror line, type 0,0 and press Enter. 7. Toggle on Polar Tracking, move the cursor horizontally to the left— beyond the building—and click to specify a horizontal mirror line. Press Enter to complete the command, and decline to erase the source object. A copy of the furniture system appears symmetrically in the lower-left building quadrant (see Figure 4.27). FIGURE 4.27 Mirroring a furniture grouping 8. Save your work as Ch4-H.dwg (or Ch4-H-metric.dwg). J The origin point is at the center of the sample office building.
8 2 Chapter 4 • Editing Entities Grip Editing All objects have grips, the square blue symbols that appear in AutoCAD at significant points when objects are selected without issuing any command. Grips provide an alternative means of accessing a number of editing commands, including STRETCH, MOVE, ROTATE, SCALE, and MIRROR. Let’s explore grip editing: 1. If the file is not already open from performing the previous step, go to the book’s web page, browse to Chapter 4, download the file Ch4-H. dwg (or Ch4-H-metric.dwg), and open it. In Reception, the sofa seating group is oriented horizontally, but this doesn’t respond to the geometry of the space. 2. Select the inner line of the window wall directly below the sofas, right-click, and choose Properties from the context menu. Make a note that the angle of this line is 173.77 degrees. Press Esc to deselect. 3. Click both sofas and the coffee table in between them to select all three. Single blue grips appear on the sofas because they are blocks (see Chapter 7, “Organizing Objects,” for more on blocks). 4. Click this grip in the center of the coffee table to activate it. The command prompt reads as follows: ff STRETCH ff GRIP_STRETCH Specify stretch point or [Base point Copy Undo eXit]: Press the spacebar. The command prompt changes to: ff MOVE ff GRIP_MOVE Specify move point or [Base point Copy Undo eXit]: 5. Press the spacebar again. The command prompt now says: ff ROTATE ff GRIP_ROTATE Specify rotation angle or [Base point/Copy/Undo/Reference/eXit]: Certification Objective
Grip Editing 8 3 6. Type 'CAL to invoke the command-line calculator transparently. Type 173.77-180, and press Enter to have AutoCAD calculate the negative rotation angle for you (-6.23 degrees in this case). Remember that negative angles rotate objects clockwise by default. The seating group rotates to match the orientation of the window wall that it is in front of. 7. Press Esc to deselect all. Figure 4.28 shows the final result. 8. Your drawing should now resemble Ch4-Final.dwg (or Ch4-Finalmetric.dwg), which is available among the book’s companion download files at www.sybex.com/go/autocad2014essentials. FIGURE 4.28 Completed office building drawing J Using an apostrophe before a command issues it transparently so that it works on top of another command without canceling it.
8 4 Chapter Chapter 4 • Editing Editing Entities Entities The Essentials and Beyond In this chapter, you learned how to edit drawings first by making selections, and then by moving, copying, rotating, and scaling objects. You created individual and associative rectangular and polar arrays; used the Trim, Extend, Lengthen, Stretch, Offset, and Mirror tools; and edited with grips. In short, you learned how to draw in AutoCAD. Congratulations are in order! Additional Exercise I Explore the BREAK, JOIN, and OVERKILL commands on your own. As the name suggests, the Break tool is used to interrupt an object at one or two points (leaving a gap). Join is used to connect two or more collinear lines into single segments. Overkill eliminates coincident lines. All three are used to clean up drawings. Break Join Overkill
CHAPTER 5 Shaping Curves For many years, the AutoCAD® program wasn’t very sophisticated when it came to shaping curves. Sure, you could create circles, arcs, and ellipses, but shaping complex curves wasn’t accurate compared to the capabilities of programs such as Autodesk® Maya® or Autodesk® 3ds Max®. In AutoCAD 2011, all this changed with the introduction of an all-new SPLINE command that offered much more flexibility in shaping true NURBS (nonuniform rational B-spline) curves using fit points or control vertices. AutoCAD 2014 expands on this by giving you the ability to shape curves in any way you can imagine and even use them to model surfaces, which you’ll learn more about in Chapter 17, “Modeling in 3D.” I Drawing and editing curved polylines I Drawing ellipses I Drawing and editing splines I Blending between objects with splines Drawing and Editing Curved Polylines The simplest curved objects are circles and arcs (which are just parts of circles), because they curve with a constant radius from a center point. In the following steps, you will chain a series of arcs and/or lines together in a single polyline object, which not only streamlines editing and selection but also ensures smooth curvature between adjacent arcs. 1. Go to the book’s web page at www.sybex.com/go/ autocad2014essentials, and browse to Chapter 5 to get the files Ch5-A.dwg (or Ch5-A-metric.dwg) and Pond.jpg. Place them in the same folder on your hard drive, and open the drawing file in AutoCAD (see Figure 5.1).
8 6 Chapter 5 • Shaping Curves A FIGURE 5.1 Initial landscape plan 2. You will begin by drawing curved pathways surrounding the lake. Click the Polyline tool on the Draw panel of the ribbon. Click the first point at point A as shown in Figure 5.1. Type A (for Arc), and press Enter. 3. Toggle off Ortho mode if it is on. Observe that the arc you are drawing may curve the wrong way, against the curvature of the lake (see Figure 5.2). The command prompt reads: Specify endpoint of arc or [Angle Center Direction Halfwidth Line Radius Second pt Undo Width]: 4. Type S (for Second Point), shown as B in Figure 5.2, and press Enter. Normally, polyline arcs are defined by two points, and by using the second point option, you are choosing the arc to be formed by three points so that you can determine its direction of curvature. Certification Objective
Drawing and Editing Curved Polylines 8 7 B FIGURE 5.2 The direction of the default polyline arc opposes the curvature of the lake. 5. Right-click the Object Snap toggle in the status bar and select Node. By turning on Node running object snap, you will be able to snap arcs to all the point objects surrounding the lake. Turn on Endpoint running object snap if it is not already on. Click B as shown in Figure 5.2. 6. Click each subsequent node around the left half of the lake until you reach point C in Figure 5.3. Press Enter to end the PLINE command. C FIGURE 5.3 Drawing a polyline around the left half of the lake 7. Press the spacebar to repeat the last command. Click point D shown in Figure 5.4, type A (for Arc), and press Enter. J The point objects in the sample file are meant to guide you in the exercise. Points typically aren’t necessary when drawing curves on your own.
8 8 Chapter 5 • Shaping Curves E D FIGURE 5.4 Drawing another polyline around the right half of the lake 8. Type S (for Second Point), press Enter, and snap to the node adjacent to point D. 9. Click each subsequent node around the right side of the lake until you reach point E in Figure 5.4. Press Enter. 10. Type O (for Offset), and press Enter. Type 6 (or 2 m), and press Enter. Click the left polyline you drew around the lake in steps 1–6, and then click a point on the side of the polyline away from the lake. Click the right polyline, and click outside the lake. Click the outer arc surrounding the pentagonal structure, and then click outside the lake. 11. Click the Trim tool in the Modify panel. Press Enter to select all objects as potential cutting edges, and click the portions of the arcs that overlap in the top highlighted area in Figure 5.5. Zoom into the lower highlighted area, and trim the arcs so that they meet at their endpoints. Press Esc to end the TRIM command. Certification Objective
Drawing and Editing Curved Polylines 8 9 FIGURE 5.5 Trimming polylines and arcs 12. Pan over to the building at the bottom of the lake. We’d like the ends of the paths to open up to the building. Click the lower-left polyline to select it. Click the endpoint grip, move it down a short distance, and click again (see Figure 5.6). You can’t get the end of the path to open up without distorting the path farther up because it’s all part of the same arc segment. FIGURE 5.6 Adjusting an existing polyline with its grips Certification Objective
9 0 Chapter 5 • Shaping Curves 13. Press Esc, and then click the Undo button in the Quick Access toolbar. 14. Click the Arc tool in the Draw panel, hold Shift down and right-click, and choose Nearest from the context menu. Click points A, B, and C in Figure 5.7 to shape the arc as shown. A B C F D E FIGURE 5.7 Drawing new short-radius arcs and snapping them along the longer existing arcs 15. Press Enter twice to end, and restart the ARC command. Type NEA (for Nearest), press Enter, and click points D, E, and F in Figure 5.7. 16. Zoom in and trim away the portions of the original polylines that extend beyond the new arcs you’ve just drawn. 17. Type J (for Join), and press Enter. Select all five objects that comprise the outer path (three arcs and two polylines). Press Enter, and the command line reads: 13 segments joined into 1 polyline There are 13 segments if you include all the arcs that make up the two polylines. You are left with a single polyline marking the outer edge of the path. 18. Press the spacebar to repeat the JOIN command. Select the three objects along the inner edge of the path, which include two polylines and the arc above the pentagon. Press Enter, and multiple segments are joined into one polyline (see Figure 5.8). Certification Objective Use JOIN to connect collinear lines even if there is a gap between them. JOIN is the antidote to BREAK. I
Drawing Ellipses 9 1 FIGURE 5.8 The curving path around the lake joined into two objects Should You Use JOIN or PEDIT? In previous versions of AutoCAD, objects first had to be converted into polylines and then joined using the polyline editing command called PEDIT. The streamlined JOIN command makes the older workflow unnecessary. Use it on lines, 2D and 3D polylines, arcs, elliptical arcs (sections of ellipses), and/or helices. Multiple object types can be joined at once. The resulting object type depends on what was selected. Drawing Ellipses AutoCAD can draw perfect ovals, which are mathematically known as ellipses. Instead of stretching a cord from two pins to a moving pencil point (which is how you draw an ellipse by hand), in AutoCAD you specify the lengths of its major and minor axes (see Figure 5.9).
9 2 Chapter 5 • S haping Curves Minor Axis Major Axis FIGURE 5.9 An ellipse’s major and minor axes In this exercise, you will draw an ellipse and distribute shrubs along its edge: 1. Zoom into the area in the lower left where the remaining point objects are located. 2. Type REGEN (for Regenerate), and press Enter. The size of point objects is recalculated when the drawing is regenerated. 3. Open the Ellipse menu in the Draw panel, and choose the Center method. Click the center point, the end of the major axis, and the end of the minor axis, as shown in Figure 5.10. End of major axis Center of ellipse End of minor axis FIGURE 5.10 Drawing an ellipse 4. Type BR (for Break), press Enter, and select the ellipse. The command prompt reads: Specify second break point or [First point]: Type F (for First Point), and press Enter. Certification Objective
Drawing Ellipses 9 3 5. Right-click the Object Snap toggle in the status bar, and select Quadrant from the context menu. Click the quadrant point (north, south, east, or west points of any circle) opposite the point object marking the end of the major axis (see Figure 5.10), and then click the aforementioned point object itself to break the ellipse in half. The lower half of the ellipse remains, leaving an elliptical arc. 6. Type DIV (for Divide), and press Enter. Select the elliptical arc, and press Enter. The command prompt reads: Enter the number of segments or [Block]: Type B (for Block), and press Enter. You’ll learn more about blocks in Chapter 7, “Organizing Objects.” 7. A block called Shrub is predefined, so at the next command prompt: Enter name of block to insert: type Shrub, and press Enter. 8. Press Enter to accept the default when asked if you want to align the block with the selected object. (It doesn’t matter in this case because the Shrub block is a circle.) 9. Type 13 (for the number of segments), and press Enter. The DIVIDE command always creates one less point or block than the number of segments into which the object is divided. Twelve “shrubs” appear along the elliptical arc (see Figure 5.11). 10. Delete the three points used in drawing the ellipse, the elliptical arc itself, and the black circle, which is the original Shrub block. You deleted the layout geometry and are now left with precisely positioned shrubs. FIGURE 5.11 Dividing an elliptical arc with blocks J Breaking an ellipse, arc, or circle works in a counterclockwise fashion. Certification Objective
9 4 Chapter 5 • Shaping Curves Drawing and Editing Splines Splines are the equivalent of a French curve in traditional drafting, used for making curves of constantly changing radii. Splines have been part of AutoCAD for many releases, but the SPLINE command was completely overhauled in AutoCAD 2011. The new splines in AutoCAD are NURBS-based curves (the same type used in Autodesk® Alias® Design Surface, Maya, 3ds Max, and many other high-end 3D programs). There are two types of NURBS curves: I Those defined by control vertices (CVs), which don’t lie on the curve except at its start and endpoints I Those defined by fit points, which lie on the curve itself You have more control over shaping curves with CVs, but if you want the curve to pass through specific points, or want the curve to have sharp kinks, then Fit Points mode is preferable. Fortunately, it is easy to switch between CVs and Fit Points editing modes, so you can make up your mind about which method to use to suit the situation. Working with Control Vertices CVs offer the most flexibility in terms of precisely shaping NURBS curves. A control frame connects CVs and represents the maximum possible curvature between adjacent CVs. You will now draw a CV spline around the lake: 1. Toggle off Object Snap, Ortho, and Polar Tracking modes on the status bar if any of them are on. Type SPL (for Spline), and press Enter. The command prompt reads: Current settings: Method=Fit Knots=Chord Specify first point or [Method Knots Object]: Type M (for Method), and press Enter. 2. The command prompt reads: Enter spline creation method [Fit CV] <Fit>: Type CV (for Control Vertices), and press Enter. Click the first point anywhere along the edge of the lake. 3. Continue clicking points all the way around the lake. When you get close to the first point, type C (for Close) and press Enter. Click the spline you just drew to reveal its CVs (see Figure 5.12). Certification Objective CV curves are typically roughed-in initially and then are refined in shape immediately afterward. I
Drawing and Editing Splines 9 5 FIGURE 5.12 Drawing a rough CV spline around the lake 4. Position the cursor over a CV, and observe the multifunction grip menu. Select Stretch Vertex, move the cursor, and click to relocate that particular CV. 5. Try adding and removing vertices using the corresponding choices on the multifunction grip menu (see Figure 5.13). FIGURE 5.13 Adding and removing vertices from a CV spline using multifunction grips 6. Refining a vertex transforms one vertex into two adjacent vertices. Try refining vertices in areas where the curvature is changing rapidly. 7. Another way to affect the shape of a spline is to adjust the weights of individual CVs. Double-click the spline itself (rather than a CV or the control frame) to invoke the SPLINEDIT command. The prompt reads: Enter an option [Open Fit data Edit vertex convert to Polyline
9 6 Chapter 5 • Shaping Curves Reverse Undo eXit] <eXit>: Type E (for Edit Vertex), and press Enter. 8. The prompt now reads: Enter a vertex editing option [Add Delete Elevate order Move Weight eXit] <eXit>: Type W (for Weight), and press Enter. 9. Before entering a weight value, you must select the vertex in which you’re interested. Zoom out until you can see all the vertices, locate the red one, press Enter repeatedly to choose the default option (Next), and move the red CV one position at a time until your chosen CV turns red. 10. Type 2, and press Enter (see Figure 5.14). The spline will get closer to the red CV and its control frame. Type .5, and press Enter again; the curve moves farther away from the control frame. Type a value appropriate to your particular situation, and press Enter. We set a weight of 0.75 for the CV shown in Figure 5.14 to push it away from the control frame and more closely match the shape of the lake. The weights you need to enter depend entirely on exactly where you placed the CVs when creating the curve in step 2. Increase the weight of this CV. The curve is drawn closer to the control frame near the weighted CV. FIGURE 5.14 Adjusting the weight of a CV I Vertices with higher weights pull the curve toward the control frame and vertices with weights below 1 (but above 0) push the spline farther away.
Drawing and Editing Splines 9 7 11. Type X (for Exit), and press Enter. Press X and Enter twice more to exit SPLINEDIT fully. Sketch and Rebuild CVs Instead of stretching, adding, removing, refining, and/or adjusting CVs, you can sketch spline curves freehand. The SKETCH command is admittedly difficult to use with a mouse, so if you have a stylus and a drawing tablet, try using them for a more natural drawing feel. Unfortunately, sketching splines usually results in an uneven distribution of CVs, but this can be rectified by using CVREBUILD. For an alternative natural drawing technique, draw splines on a tablet with SKETCH (using SPLINE in its type option) and then redistribute the resulting CVs with CVREBUILD. The CVREBUILD command’s Rebuild Curve dialog box is shown here: 12. Continue adjusting the spline until it closely matches the outline of the lake. 13. Type IM (for Image), and press Enter. The External References palette appears. (You’ll learn more about this palette in Chapter 9, “Working with Blocks and Xrefs.”) The lake that you have been tracing is an image that you will now detach. 14. Right-click Pond in the External References palette, and choose Detach Image. Close the External References palette. Select the pond spline, and change its color to Blue in the Properties panel (see Figure 5.15). The pond is now represented by a blue curve rather than a blue image.
9 8 Chapter 5 • Shaping Curves FIGURE 5.15 Pond shown as a spline rather than an image Working with Fit Points Fit point splines are straightforward in the sense that the fit points you click lie on (or very close to) the curve itself. Controlling the shape of a fit curve on the most basic level is a matter of adding more fit points in strategic locations. There are a few advanced options affecting the shape of a spline in between fit points (Tangent, Tolerance, Kink, and Knot Parameterization), and you will use Kink in this exercise to establish sharp points on the spline. 1. Zoom into the area at the bottom of the lake where you distributed the shrubs earlier in this chapter in an elliptical arc. More specifically, zoom into the grouping of five points. Type REGEN, and press Enter to regenerate the display and thus automatically resize the point objects. 2. Expand the Draw panel, and click the Spline Fit tool at the top left. Toggle on Object Snap mode in the status bar (with Node snap on), and click the top point, the point on the right, the bottom, and then the one on the left. Type C (for Close), and press Enter. The fit curve looks very much like a circle, although it is not perfectly round (see Figure 5.16). This will be the start of an abstract tree representation.
Drawing and Editing Splines 9 9 FIGURE 5.16 Snapping spline fit points to point objects 3. Toggle on Dynamic Input on the status bar. Select the spline you just drew, type SPLINEDIT, and press Enter. Choose Fit Data from the dynamic input menu. Then choose Add from the next dynamic input menu that appears. 4. The prompt reads: Specify existing fit point on spline <exit>: Click the top point. 5. The prompt now says: Specify new fit point to add <exit>: This particular command requires that you snap the new fit point, so type NEA (for Nearest) and press Enter. Click the curve in between the top and right points. Press Enter four times to exit SPLINEDIT fully. 6. Another way to add fit points is with the multifunction grips, although this method doesn’t work on the first point. To use this feature, click the spline to select it, hover the cursor over the right point, and choose Add Fit Point from the menu that appears. Hold Shift, right-click, and choose Nearest from the context menu. Click a point between the right and bottom points. 7. Repeat the previous step twice more, adding additional fit points between the bottom, left, and top points (see Figure 5.17).
100 Chapter 5 • Shaping Curves FIGURE 5.17 Adding additional fit points between the initial points 8. Double-click the spline itself to invoke the SPLINEDIT command without typing. Type F (for Fit Data), and press Enter. The prompt reads: Enter a fit data option [Add Open Delete Kink Move Purge Tangents toLerance eXit] <eXit>: Type K (for Kink), and click eight points in between all the existing fit points (see Figure 5.18). Press Enter three times to exit the command fully. Kinks FIGURE 5.18 Adding kinks to the fit points spline 9. Click each kink grip, and move it in toward the center to create an abstract representation of a tree. Delete the five point objects that helped you lay out the tree (see Figure 5.19). If you have trouble selecting point objects, try changing their size with the DDPTYPE and REGEN commands.
Blending Between Objects with Splines 101 FIGURE 5.19 Abstract tree created by stretching kinks in a fit point spline Blending Between Objects with Splines The BLEND command creates a CV spline in between two selected lines, circular or elliptical arcs, splines, or any combination of these object types. Blend curves join the endpoints of the two objects with a curve having either tangent or smooth continuity. There is a subtle difference between these types of blending. A blend curve with tangent continuity has its control frame parallel to the control frame of the adjacent curve. A blend curve with curvature continuity not only has its control frame parallel to the control frame of the adjacent curve, but the control frames have equal lengths. In simpler terms, tangent continuity is smooth, and smooth continuity is “perfectly smooth.” In the following steps, you will create blend curves with two types of curvature: 1. Pan over to the other “tree” to the left of the tree you’ve drawn with kinks. Type BLEND, and press Enter. 2. The prompt reads: Continuity = Tangent Select first object or [CONtinuity]: Select a flat arc and a tight arc, and the command is finished. A CV spline with tangent continuity blends between the two arcs.
102 Chapter 5 • Shaping Curves 3. Press the spacebar to repeat BLEND, type CON (for Continuity), press Enter, type S (for Smooth), and press Enter again. Click two adjacent arcs to create another blend curve (see Figure 5.20). Smooth continuity Tangent continuity FIGURE 5.20 Blending between arcs with different types of continuity 4. Continue blending all the adjacent curves in the tree. Delete the point object at the center. Figure 5.21 shows the completed drawing. FIGURE 5.21 Completed landscape plan 5. Your drawing should now resemble Ch5-B.dwg (or Ch5-B-metric .dwg), which is available at this book’s web page.
Blending Between The Essentials Objects with and Beyond Splines 103 The Essentials and Beyond You have learned how to shape many types of curvilinear objects in this chapter, including circular and elliptical arcs, polylines, ellipses, and CV and fit point NURBS-based splines. You’ve broken and joined objects, and blended smoothly between adjacent curves. In short, you now have the skills to shape just about any curve you can imagine with a fine degree of precision, which is what AutoCAD is all about. Additional Exercise I Explore the HELIX command on your own. The HELIX command creates spirals and helices. You are welcome to stick with two dimensions for now and create spirals with this command. When you learn how to navigate and model in 3D (in Chapters 16 and 17), you can use this command to create springs, screw threads, or even DNA.
CHAPTER 6 Controlling Object Visibility and Appearance Layers control objects whether they are visible or hidden. All objects have properties that control their appearance—properties such as color, linetype, lineweight, and so on. The layers to which objects are assigned usually control general object properties, but these properties can be set on a per-object basis as well. This chapter explores the many AutoCAD® tools associated with layers that illustrate the importance of layers in managing the complexity of design. I Changing object properties I Setting the current layer I Altering the layer assignments of objects I Controlling layer visibility I Applying linetype I Assigning properties by object or by layer I Managing layer properties Changing Object Properties All objects have properties controlling their appearance. When you draw a line, you are ultimately specifying its geometric properties (the start point and the endpoint). Likewise, when you draw a circle, you are just specifying its center point and radius properties. Geometric properties are the most important factor governing how objects look and in determining where the objects are in space.
106 Chapter 6 • Controlling Object Visibility and Appearance In addition to geometric properties, all objects share a short list of general properties: layer, color, linetype, linetype scale, lineweight, transparency, and thickness. Although general properties are assigned on a per-object basis, they are usually controlled by using layers. Let’s explore object properties in an existing drawing and then learn how to change properties and merge the layers to which objects are assigned: 1. Go to the book’s web page at www.sybex.com/go/ autocad2014essentials, browse to Chapter 6, get the file Ch6-A.dwg (or Ch6-A-metric.dwg), and open it (see Figure 6.1). This is the architectural plan for a hypothetical small office. FIGURE 6.1 Small office plan 2. Zoom into the reception desk at the center of the small office plan. 3. Toggle on the Quick Properties mode in the status bar. 4. Click on the line of the desk immediately adjacent to the Reception text object; the Quick Properties panel appears at the top right of the selected object on the drawing canvas. Click the Desk-High layer name to activate the Layer drop-down menu (see Figure 6.2). Certification Objective
C hanging Object Properties 107 FIGURE 6.2 Targeting an object property using Quick Properties mode 5. Select the Desk layer in the drop-down (see Figure 6.3), and press the Esc key to exit Quick Properties mode. Observe that the line whose layer property you changed now appears violet, like the other objects on the Desk layer. FIGURE 6.3 Assigning a different layer to the selected object 6. Expand the Layers panel on the Home tab of the ribbon. 7. Click the Merge tool. The command prompt reads: Select object on layer to merge or [Name]: 8. Click one of the brown lines in the upper portion of the reception desk and press Enter. J You can change the properties of multiple objects simultaneously by selecting more than one object in Quick Properties mode. However, only the properties that the selected items have in common are displayed.
108 Chapter 6 • Controlling Object Visibility and Appearance 9. Click the violet line you changed to the Desk layer in step 5 and press Enter. The command prompt reads: Select object on target layer or [Name]: ******** WARNING ******** You are about to merge layer "Desk-High" into layer "Desk". Do you wish to continue? [Yes/No] <No>: 10. Press Y (for Yes), and then press Enter to continue. The Desk-High layer is deleted, and the objects that were on it have been reassigned to the Desk layer. The LAYMRG command is done. 11. Expand the Properties panel, and click the List tool. Pan over and select the Business Development text object by clicking on it and pressing Enter. The AutoCAD Text window appears, displaying the following property information: TEXT Layer: "Title" Space: Model space Handle = 71e Style = "Standard" Annotative: No Typeface = Arial mid point, X= 193.8805 Y= 132.8080 Z= 0.0000 height 7.5000 text Business Development rotation angle 0 width scale factor 1.0000 obliquing angle 0 generation normal This list might be helpful if you were looking for a particular piece of information, but you can’t edit any of the properties directly. Close the AutoCAD Text window. 12. Select the View tab on the ribbon and, under Panels, click the Properties tool to open the Properties panel. 13. Select the Business Development text object you selected in step 11. Many of its properties appear in the panel (see Figure 6.4). Property values displayed on a white background are editable; those on a gray background are for your information only. I Use the LAYDEL command to delete a layer and everything on it. Be careful, though, to avoid deleting valuable information. Certification Objective
Setting the Current Layer 109 FIGURE 6.4 Editing a value in the Properties panel 14. Select the words “Business Development” in the Contents property, type Marketing, and press Enter. Press Esc to deselect the text object. The department’s name has been changed. You can now close the Properties panel. Setting the Current Layer Objects are always drawn on the current layer, and there is only one current layer at any given time. Every drawing has at least one layer, layer 0 (zero), which is current by default when you create a new drawing. AutoCAD has another special layer called Defpoints, which is automatically created when you add associative dimensions to a drawing (see Chapter 11, “Dimensioning”). Let’s experiment with setting the current layer by drawing a few objects: 1. Using the Ch6-A.dwg (or Ch6-A-metric.dwg) file, zoom into the Manager’s office. If this file is not open, find it on the book’s web page. 2. Click the Rectangle tool on the Draw panel, and click a point a few inches (no need to measure) from the lower-left corner of the room. J Although the LIST command shows some property information that does not appear in the Properties panel, most people prefer using the panel because much of the data is directly editable. J You cannot delete or rename layer 0 or Defpoints. It’s okay to draw on layer 0, but not on Defpoints.
110 Chapter 6 • Controlling Object Visibility and Appearance Type @18,72 (or @45,180 for metric) and press Enter to create a credenza in the Manager’s office (see Figure 6.5). Credenza FIGURE 6.5 Drawing furniture on layer 0 3. Select the rectangle you drew in the previous step, and change its Layer assignment to Furniture in the Quick Properties window that appears. Press Esc to deselect. 4. If you plan on drawing more than one object, a more efficient approach is to set the current layer prior to drawing, so that the new object will have the proper layer assignment automatically. Open the Layer drop-down menu in the Layers panel, and click on or to the right of the word Furniture to set this layer as current. Notice that Furniture appears “on top” when the drop-down is closed (see Figure 6.6); Furniture is now the current layer. FIGURE 6.6 Setting Furniture as the current layer using the drop-down menu in the Layers panel I Press Shift, right-click, and choose the None object snap to override any running object snap modes whenever necessary.
Setting the Current Layer 111 5. Pan over to the Marketing space. 6. Click the Rectangle tool on the Draw panel, and click a point a few inches (without measuring) from the lower-right corner of the room. Type @-18,72 (or @-45,180 for metric), and press Enter to create a credenza in Marketing (see Figure 6.7). Current layer Credenza FIGURE 6.7 Drawing another credenza on the Furniture layer 7. Select the rectangle you drew in the previous step, and verify that it is on the Furniture layer in the Quick Properties window that appears. Press Esc. 8. Pan over to the closet in Marketing. One of the lines representing shelves is missing. You will draw the missing line on the same layer as the existing shelf line. 9. Rather than selecting the existing shelf line by learning its layer name and then setting that layer as current, there is a more efficient approach. In the Layers panel, click the Make Object’s Layer Current tool. Click the existing shelf line in Marketing’s closet. The layer appearing at the top of the Layer drop-down menu is Millwork, which shows that it’s now the current layer. 10. Toggle on Endpoint and Perpendicular running object snap modes on the status bar. 11. Click the Line tool on the Draw panel, and draw the line shown in Figure 6.8. Press Esc to end the LINE command.
112 Chapter 6 • Controlling Object Visibility and Appearance Draw this line Make this object’s layer current FIGURE 6.8 Drawing a line after using the Make Object’s Layer Current tool Altering the Layer Assignments of Objects Although you have already changed the layer assignments of objects using Quick Properties, there are more efficient methods of doing so, some of which do not require you to remember a layer name. Let’s explore several methods for changing the layer assignments of existing objects: 1. Using the Ch6-A.dwg (or Ch6-A-metric.dwg) file, zoom into the Marketing office. If this file is not open, find it on the book’s web page. 2. Toggle off Quick Properties mode on the status bar. 3. Select the coffee table. Notice that the entry in the Layer drop-down in the Layers panel changes to layer 0; this does not mean that layer 0 is current (Millwork is), only that the selected item is on layer 0. 4. Open the Layer drop-down menu, and click Furniture (see Figure 6.9) to change the layer assignment of the selected items. Press Esc to deselect. 5. Pan over to the Lounge. 6. Click the Match tool in the Layers panel, select the coffee table in the Lounge, and press Enter. The command prompt reads: Select object on destination layer or [Name]: 7. Click one of the sofas in the Lounge and press Enter; the LAYMCH command ends. The coffee table is now assigned to the same layer as the sofas (Furniture). I A preview of property changes appears on screen as you hover over items in the Layers drop-down menu or the Properties panel.
Altering the Layer Assignments of Objects 113 FIGURE 6.9 Changing layer assignment with the Layer drop-down menu 8. Pan to the Manager’s office. 9. Click the Match Properties tool in the Clipboard panel on the Home tab of the ribbon. Select the credenza in the Manager’s office and press Enter. The command prompt reads: Select destination object(s) or [Settings]: 10. Type S (for Settings), and press Enter; the Property Settings dialog box appears. You can match many properties in addition to layers with this tool (see Figure 6.10). Click OK. FIGURE 6.10 The Property Settings dialog box allows you to match much more than layers. Certification Objective
114 Chapter 6 • Controlling Object Visibility and Appearance 11. Click the desk in the Manager’s office and press Enter; the desk turns green because it is now on the Furniture layer. Press Esc to exit the MATCHPROP command. Merging Layers In AutoCAD 2014, you can merge the contents of multiple layers into a single layer. First, select the layers you wish to merge in the Layer Properties Manager (using the Ctrl key to select multiple nonsequential layers), right-click, and select Merge Selected Layers To. You are then presented with a dialog box where you can select the single destination layer from a list. The source layers are automatically purged after their contents are merged into the destination layer. Controlling Layer Visibility In traditional drafting, separate drawings would have to be made for the floor plan and the reflected ceiling plan to represent the floor and ceiling of the same space. In AutoCAD, simply displaying some layers while hiding others allows you to create some of the drawings required to describe the space graphically. To understand better how to do this, you need to learn how to toggle layer status, isolate layers to work without distraction, and save layer states to recall the layer status of multiple layers quickly. Toggling Layer Status In addition to having properties such as color, linetype, lineweight, and so on, layers have states that can be toggled, including On/Off, Thaw/Freeze, and Lock/ Unlock. As you’ll see in the following steps, layer states control the visibility and editability of the objects assigned to layers: 1. Using the Ch6-A.dwg (or Ch6-A-metric.dwg) file, zoom out to show the entire office. If this file is not open, find it on the book’s web page. 2. Expand the Layers panel, and click the Turn All Layers On tool. You now see the switches ($ symbols), downlights, and header layers. Figure 6.11 shows the result.
Controlling Layer Visibility 115 FIGURE 6.11 The Small Office plan with all layers on 3. Open the Layer drop-down menu in the Layers panel, and click the Appliance layer’s lightbulb icon to toggle it off. Toggle off the Desk layer as well. Click outside the Layer drop-down menu to close it. 4. Another approach to turning layers off doesn’t require that you know layer names. Click the Off tool in the Layers panel, and click the following objects: sink, door, chair, plant, stairs, low wall, low wall’s pattern fill, text, and the porch. Click a kitchen cabinet and the command prompt reads: Layer "Millwork" is current, do you want to turn it off? [Yes/No] <No>: 5. Type Y (for Yes), and press Enter. Press Esc to end the LAYOFF command. Figure 6.12 shows the result. 6. Open the Layer drop-down menu in the Layers panel, and set layer 0 as current. 7. Click Zoom Extents in the Navigation bar. Notice that there is a gap between the bottom wall of the building and the lower edge of the drawing canvas. Even though it is off, the Porch layer is still defining the extents of the drawing. J If you turn the current layer off, then anything you draw subsequently will be hidden.
116 Chapter 6 • Controlling Object Visibility and Appearance FIGURE 6.12 Reflected ceiling plan created by toggling layers off 8. Open the Layer drop-down menu in the Layers panel, and freeze the Porch layer. Press Esc to close the drop-down menu. 9. Click Zoom Extents in the Navigation bar again. The gap disappears because the Porch layer is no longer calculated when it is frozen and therefore is no longer part of the drawing extents. 10. Expand the Layers panel, and click the Lock tool. Select one of the lights. The Lighting layer is now locked. 11. Type E (for Erase), and press Enter. Click on a different light, and observe a tiny padlock appear near the object (see Figure 6.13). You can’t select the object because it is locked. In order to see the padlock, you must select When A Command Is Active in the Selection Preview area on the Selection tab in the Options dialog box (OPTIONS command). FIGURE 6.13 Objects on locked layers cannot be selected. I Locking layers doesn’t provide security other than disallowing selection.
Controlling Layer Visibility 117 Isolating Layers You can quickly isolate one or more layers to work on them without the visual clutter of all the other layers. Let’s try out Isolation mode: 1. Use the Ch6-A.dwg (or Ch6-A-metric.dwg) file. If this file is not open, find it on the book’s web page. 2. Click the Isolate tool on the Layers panel, and then make a crossing selection through one of the windows. Press Enter and all the other layers disappear (see Figure 6.14). FIGURE 6.14 Isolating a couple of layers for focused work 3. Expand the Layers panel, and click the Copy Objects To New Layer tool. Select each one of the nine sill lines on the inside of the building and press Enter. The command prompt reads: Select object on destination layer or [Name] <Name>:
118 Chapter 6 • Controlling Object Visibility and Appearance 4. Type N (for Name), and press Enter. The Copy To Layer dialog box appears (see Figure 6.15). Select Header from the Destination Layer list, click OK, and press Enter. There are now nine lines on the Sill layer and nine duplicate lines on the Header layer. FIGURE 6.15 Selecting a layer in the Copy To Layer dialog box 5. Click the Unisolate tool on the Layers panel. The layers return to the way they were before you used the Isolate tool. 6. Type LAYOFF, and press Enter. Click one of the sills on the outside of the building to turn off the Sill layer and press Enter. Open the Layer drop-down menu, and toggle on the Header layer. 7. Zoom into one of the lower windows, and click the Distance tool in the Utilities panel. Click points A and B shown in Figure 6.16 to measure the wall thickness. The command prompt reads: Distance = 5.0000, Angle in XY Plane = 270, Angle from XY Plane = 0 Delta X = 0.0000, Delta Y = -5.0000, Delta Z = 0.0000 A B FIGURE 6.16 Measuring the wall thickness with DISTANCE
Controlling Layer Visibility 119 8. Press Esc to cancel the DISTANCE command. 9. Type O (for Offset), press Enter, type 5 (or 12.7 for metric), and press Enter again. Click the header line in the window opening, and then click below it to offset a line on the outer edge of the wall. 10. Continue clicking each header and a point outside the building to offset a second header line in each window opening. Press Enter to end the OFFSET command when done. The reflected ceiling plan is complete. Saving Layer States In this section, you will learn how to save collections of layer states for later recall. You have already created a reflected ceiling plan in this chapter, and you will now save it as a layer state so that you won’t have to repeat all the work of toggling layer states in the future. 1. Use the Ch6-A.dwg (or Ch6-A-metric.dwg) file. If this file is not open, find it on the book’s web page. 2. Open the drop-down menu directly above the Layer drop-down (it says Unsaved Layer State by default). Select New Layer State in the drop-down menu (see Figure 6.17). FIGURE 6.17 Saving a new layer state 3. Type Reflected Ceiling Plan in the New Layer State To Save dialog box and click OK. The closed drop-down now says Reflected Ceiling Plan. 4. Expand the Layers panel, and click the Turn All Layers On tool. 5. Expand the Layers panel again, and click the adjacent Thaw All Layers tool.
120 Chapter 6 • Controlling Object Visibility and Appearance 6. Click the Freeze tool in the Layers panel, and select the following objects: light, switch, header, and computer. The layers Lighting, Electrical, Header, and Equipment are frozen. Press Enter to end the LAYFRZ command. 7. Open the Layer State drop-down menu in the Layers panel, and click New Layer State. Type Furniture Plan in the New Layer State To Save dialog box and click OK. 8. Open the Layer State drop-down menu, and select Reflected Ceiling Plan (see Figure 6.18). All the layer states associated with the Reflected Ceiling Plan are immediately toggled. Switch back to the Furniture Plan state, and you’ll see the value in saving layer states (it saves lots of time). FIGURE 6.18 Accessing saved layer states from the drop-down in the Layers panel Applying Linetype In traditional drafting, you draw short, interrupted line segments when you want to indicate what is called a hidden line. Hidden lines represent objects that are above the section plane. For example, objects such as upper cabinets, high shelves, or a roof edge are shown as hidden because they are above an imaginary section line cutting the building horizontally. In AutoCAD, lines are not interrupted (broken into multiple little pieces) to indicate hidden lines. Instead, continuous lines are assigned a linetype, and this style makes lines appear as if they are interrupted. One advantage to this is that I Using LAYERP (Layer Previous) undoes the last set of changes to layers. This is different from UNDO, which affects more than layers.
Applying Linetype 121 you can adjust the scale of the line breaks without having to redraw myriad little lines. Let’s explore linetype and linetype scale: 1. Using the Ch6-A.dwg (or Ch6-A-metric.dwg) file, zoom out to view the entire office. If this file is not open, find it on the book’s web page. 2. Open the Linetype drop-down menu in the Properties panel, and select Other at the bottom of the menu (see Figure 6.19). FIGURE 6.19 Accessing other linetypes 3. In the Linetype Manager dialog box that appears, click the Load button. Scroll down in the Load Or Reload Linetypes dialog box that appears, and select Hidden in the list (see Figure 6.20); then click OK. Hidden now appears in the Linetype Manager dialog box because this particular linetype style has been loaded in the drawing file; click OK to close the Linetype Manager dialog box. FIGURE 6.20 Loading the Hidden linetype Certification Objective
122 Chapter 6 • C ontrolling O bject V isibility a n d Appearance 4. Zoom into the closet in the Marketing space, and select both lines on the Millwork layer, representing a high shelf. 5. Open the Linetype drop-down menu in the Properties panel, and select Hidden from the menu. Now the two selected lines have the Hidden linetype assigned. 6. You still don’t see breaks in the lines because the linetype scale is too small by default. Type LTSCALE (for Linetype Scale), and press Enter. The command prompt reads: LTSCALE Enter new linetype scale factor <1.0000>: 7. Type 48 (or 50 for metric), and press Enter. The lines appear with breaks indicating that the shelf is above the section plane (see Figure 6.21). FIGURE 6.21 Hidden lines representing a high shelf in the closet 8. Select the horizontal shelf line, right-click, and choose Properties from the context menu. 9. Change Linetype Scale to 0.5 in the General section of the Properties panel (see Figure 6.22). I The factor 50 is appropriate for 1:50 metric drawings. Use LTSCALE to set the linetype scale affecting the entire drawing. Higher values of LTSCALE scale linetypes smaller. I
Assigning Properties by Object or by Layer 123 FIGURE 6.22 Adjusting the Linetype Scale property 10. Press Esc to deselect the horizontal shelf line. The breaks in the horizontal line are half as large as those in the vertical segment (see Figure 6.23). Close the Properties panel. Both lines’ linetype scales are affected by LTSCALE. This line’s linetype scale property was changed. FIGURE 6.23 Scaling the linetype of an individual object Assigning Properties by Object or by Layer Properties such as color, linetype, and lineweight are typically assigned by layer rather than by object. There is a special property value called ByLayer that passes control over specific properties to the properties managed by the layer to J Alter the linetype scale of specific objects by adjusting the Linetype Scale property in the Properties panel. Lower values scale linetypes smaller.
124 Chapter 6 • Controlling Object Visibility and Appearance which the objects are assigned. As you’ll see in these steps, using the ByLayer property is a lot easier than it sounds: 1. Using the Ch6-A.dwg (or Ch6-A-metric.dwg) file. If this file is not open, find it on the book’s web page. 2. Open the Linetype drop-down menu on the Properties panel, and select Hidden (see Figure 6.24). Draw a line of arbitrary length anywhere on the canvas. FIGURE 6.24 The Properties panel settings affect all the objects you create. 3. Open the Linetype drop-down menu on the Properties panel, and select ByLayer. 4. Draw another line, and observe that it has continuous linetype. 5. If you want to change the property of a specific object, use Quick Properties instead of the drop-down menus in the Properties panel. Toggle on Quick Properties mode on the status bar. 6. Select the continuous line drawn in step 2, and change its Linetype property to Hidden (see Figure 6.25). FIGURE 6.25 Changing a specific object property 7. Draw another line, and verify that it has continuous linetype. 8. Delete all three arbitrary lines you’ve just drawn. I Objects should be assigned specific colors, linetypes, or lineweights only in exceptional circumstances.